lkml.org 
[lkml]   [2013]   [Jun]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/2] hw_breakpoint: Use cpu_possible_mask in {reserve,release}_bp_slot()
On Sat, Jun 01, 2013 at 08:21:39PM +0200, Oleg Nesterov wrote:
> fetch_bp_busy_slots() and toggle_bp_slot() use for_each_online_cpu(),
> this is obviously wrong wrt cpu_up() or cpu_down(), we can over/under
> account the per-cpu numbers.
>
> For example:
>
> # echo 0 >> /sys/devices/system/cpu/cpu1/online
> # perf record -e mem:0x10 -p 1 &
> # echo 1 >> /sys/devices/system/cpu/cpu1/online
> # perf record -e mem:0x10,mem:0x10,mem:0x10,mem:0x10 -C1 -a &
> # taskset -p 0x2 1
>
> triggers the same WARN_ONCE("Can't find any breakpoint slot") in
> arch_install_hw_breakpoint().
>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
> Cc: <stable@vger.kernel.org>

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>


\
 
 \ /
  Last update: 2013-06-15 15:01    [W:1.660 / U:0.000 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site